1. Technical Field
The present invention relates generally to a novel method for producing neutrons in a controlled manner in a novel type of neutron generator, and more particularly to a novel method and apparatus for producing commercially and medically useful isotopes by transmuting selected precursor isotopes using gamma radiation.
2. Background Art
It is well known that neutrons produce valuable isotopes used in scientific research, manufacturing, and medicine. Radioactive isotopes are employed in scientific research in fields as diverse as hydrology and life sciences. Isotopes are used in business and commerce in many manufacturing process and in the production of oil and gas. The most valuable, yet some of the most difficult to make isotopes, are used in the diagnosis and treatment of human diseases and disorders.
It is also well known that fission in nuclear reactors produces fission products that are a component of nuclear waste.
Isotopes are currently produced by electron beams, ion beams, in cyclotrons and in nuclear reactors. Some isotopes may be produced by any of the four general methods. Others by one method alone. The science of isotope production involves adding or subtracting the requisite number of nucleons (protons or neutrons) to or from the target's parent isotope to produce the desired end product in significant quantities with appropriate purity.
The transmutation reactions that change the number of protons or neutrons in the isotopes include photo nuclear reactions wherein energetic gamma photons eject neutrons from nuclei. Also high energy neutrons are able to displace or eject protons from nuclei. Transmutation reactions caused by accelerated ions such as protons, deuterons, helium nuclei and other ions collide with the nuclei of the target material to change the isotope from one to another. These reactions generally do not yield the quantity of desired product material as efficiently as reactions involving successive or singular neutron capture in the nuclear reactor. The above mentioned reactions also are not as efficient in the treatment of fission products to transmuted them to shorter lived isotopes or common stable isotopes.